From de21af38f217480ad24c856ee051613941dd5504 Mon Sep 17 00:00:00 2001
From: H1ghBre4k3r <h1ghbre4k3r@dev.bre4k3r.de>
Date: Tue, 23 Mar 2021 18:11:11 +0100
Subject: [PATCH] Add sn_mask to mask a sequence number

---
 src/main.c           |  1 -
 src/records.c        |  1 -
 src/sequencenumber.c |  7 +++++--
 src/sequencenumber.h |  9 +++++++++
 src/storage.c        | 42 +++++++++++++++++++++++++++++++++++++-----
 5 files changed, 51 insertions(+), 9 deletions(-)

diff --git a/src/main.c b/src/main.c
index 24c56d0..67481c1 100644
--- a/src/main.c
+++ b/src/main.c
@@ -36,7 +36,6 @@ void main(void) {
         return;
     }
 
-    printk("init contacts\n");
     init_contacts();
     err = init_io();
     if (err) {
diff --git a/src/records.c b/src/records.c
index 7feeb63..d1cfbed 100644
--- a/src/records.c
+++ b/src/records.c
@@ -6,7 +6,6 @@
 int ens_records_iterator_init_range(record_iterator_t* iterator,
                                     record_sequence_number_t* opt_start,
                                     record_sequence_number_t* opt_end) {
-    // TODO: if start or end is null, use currently available numbers
     iterator->sn_next = opt_start ? *opt_start : get_oldest_sequence_number();
     iterator->sn_end = opt_end ? *opt_end : get_latest_sequence_number();
     if (get_num_contacts() == 0) {
diff --git a/src/sequencenumber.c b/src/sequencenumber.c
index c688e7f..b2ddcab 100644
--- a/src/sequencenumber.c
+++ b/src/sequencenumber.c
@@ -1,10 +1,13 @@
 #include "sequencenumber.h"
 
+record_sequence_number_t sn_mask(record_sequence_number_t sn) {
+    return (sn & SN_MASK);
+}
 
 int sequence_number_eq(record_sequence_number_t a, record_sequence_number_t b) {
-    return (a & SN_MASK) == (b & SN_MASK);
+    return sn_mask(a) == sn_mask(b);
 }
 
 record_sequence_number_t sequence_number_increment(record_sequence_number_t sn) {
-    return (++sn & SN_MASK);
+    return sn_mask(++sn);
 }
\ No newline at end of file
diff --git a/src/sequencenumber.h b/src/sequencenumber.h
index 428f593..7865803 100644
--- a/src/sequencenumber.h
+++ b/src/sequencenumber.h
@@ -8,6 +8,15 @@
 
 typedef uint32_t record_sequence_number_t;
 
+/**
+ * Mask a given sequence number to get rid of MSB.
+ * TODO: maybe as #define?
+ * 
+ * @param sn sequence number to mask
+ * @return masked sequence number
+ */
+record_sequence_number_t sn_mask(record_sequence_number_t sn);
+
 /**
  * Compare to sequence numbers for equality.
  * 
diff --git a/src/storage.c b/src/storage.c
index 99df8ff..7d06abb 100644
--- a/src/storage.c
+++ b/src/storage.c
@@ -7,6 +7,7 @@
 #include <zephyr.h>
 
 #include "storage.h"
+#include "sequencenumber.h"
 
 // Maybe use this as param for init function
 #define SEC_COUNT 8U
@@ -14,12 +15,14 @@
 #define STORED_CONTACTS_INFO_ID 0
 #define CONTACTS_OFFSET 1
 #define MAX_CONTACTS 65535
-#define ADDRESS_ID 1
 
 static struct nvs_fs fs;
 
-// TODO lome: load this from flash
-static stored_contacts_information_t contact_information;
+// Information about currently stored contacts
+static stored_contacts_information_t contact_information = {
+    .oldest_contact = 0,
+    .count = 0 
+};
 
 inline storage_id_t convert_sn_to_storage_id(record_sequence_number_t sn) {
     return (storage_id_t)(sn % MAX_CONTACTS) + CONTACTS_OFFSET;
@@ -31,6 +34,24 @@ void increment_storaed_contact_counter() {
     }
 }
 
+/**
+ * Load our initial storage information from storage.
+ */
+int load_storage_information() {
+    size_t size = sizeof(contact_information);
+    int rc = nvs_read(&fs, STORED_CONTACTS_INFO_ID, &contact_information, size);
+
+    // Check, if read what we wanted 
+    if(rc != size) {
+        // Write our initial data to storage
+        rc = nvs_write(&fs, STORED_CONTACTS_INFO_ID, &contact_information, size);
+        if(rc <= 0) {
+            return rc;
+        }
+    }
+    return 0;
+}
+
 int init_contact_storage(void) {
     int rc = 0;
     struct flash_pages_info info;
@@ -39,13 +60,23 @@ int init_contact_storage(void) {
     rc = flash_get_page_info_by_offs(device_get_binding(DT_CHOSEN_ZEPHYR_FLASH_CONTROLLER_LABEL), fs.offset, &info);
 
     if (rc) {
+        // Error during retrieval of page information
         return rc;
     }
     fs.sector_size = info.size;
     fs.sector_count = SEC_COUNT;
 
     rc = nvs_init(&fs, DT_CHOSEN_ZEPHYR_FLASH_CONTROLLER_LABEL);
-    
+    if(rc) {
+        // Error during nvs_init
+        return rc;
+    }
+
+    // Load the current storage information
+    rc = load_storage_information();
+
+    printk("Currently %d contacts stored!\n", contact_information.count);
+
     return rc;
 }
 
@@ -71,13 +102,14 @@ int add_contact(contact_t* src) {
 }
 
 // TODO handle start and end
+// TODO lome: do we need this?
 int delete_contact(record_sequence_number_t sn) {
     storage_id_t id = convert_sn_to_storage_id(sn);
     return nvs_delete(&fs, id);
 }
 
 record_sequence_number_t get_latest_sequence_number() {
-    return contact_information.oldest_contact + contact_information.count;
+    return sn_mask(contact_information.oldest_contact + contact_information.count);
 }
 
 record_sequence_number_t get_oldest_sequence_number() {